Strap tensioning tool



Dec. 4, y1962 M. DERRICKSON STRAP TENSIONING TOOL 37 Filed Nov. l5, 1961United States Patent Otlice 3,666,706 Patented Dec. 4, 1952 3,066,766 STENSINING TOOL Michael 0. Derrickson, Norwood, Pa., assignor to AmericanViscose Corporation, Philadelphia, Pa., a corporation of Delaware FiledNov. 15, 1961, Ser. No. 152,590 8 Claims. (Cl. Mtl-123.6)

This invention relates to the art of applying exible straps about anarticle or group of articles and more particularly to an improved straptensioning tool.

It is an object of the invention to provide a strapping tool havingpower operated strap tensioning means and so constructed that a singlemotion on the part of the operator is elective to cut the Strap tolength and discontinue the application of power to the strap tensioningmeans.

Another object of the invention is to provide a strap tensioning toolhaving power means for tensioning a strap about one -or more articlesand a common operating member for controlling the power means andcutting the strap to length.

Toward the attainment of the foregoing objects the invention provides astrap tensioning tool having novel structural features, as will now ybeexplained by reference to the accompanying drawing showing a preferredembodiment, wherein:

FIG. l is a side elevational view of the tool showing portions of theinternal mechanism in dotted lines;

FIG. 2 is an end elevational view :of the tool;

FIG. 3 is a fragmentary plan View of the front end of the tool, certaininternal parts being shown in dotted lines;

FIG. 4 is a fragmentary side elevational view of the front end of thetool;

FIG. 5 is an elevational view of the lower portion of the tool lookingfrom the right-hand side of FIG. l;

FIG. 6 is an exploded View showing a valve constituting one of theelements of the invention; and

FIG. 7 is a sectional view taken along the line VII- VII of FIG. l.

The tool comprises a housing consisting of two castings 1t) and 11.Casting 16 forms the forward end of the tool and supports the strapengaging elements and casting 11 houses most of the driving mechanismand includes a more or less cylindrical handle portion 12. A bore 13extends longitudinally of the handle portion 12 of casting 11 and at itsforward end communicates with a conduit 14 leading to a valve, generallyindicated at 15. A hose 16 is connected to the end of handle por-tion 12and discharges into bore 13. A conduit 17 communicates at one end withvalve and at the other joins an end of a bore 18 extending rearwardlythrough the handle portion 12 parallel to bore 13. A plug 19 closes theouter end of bore 18 and a short conduit 20 connects bore 18 t-o achamber 21 within casting 11. A Ifluid motor 22, preferably an airmotor, lis mounted within chamber 21 and the drive shaft of said motoris provided with a pinion 23 situated within a hollowed-out portion ofcasting 1t). Pinion 23 meshes with a gear 24 secured to a shaft 25mounted in suitable bearings within castings 141 and 11. Shaft 25extends through the front face of casting 10 and a slotted capstan orstrap-winding drum 26 is secured to said shaft. When valve 15 is open,compressed air from line 16 passes to the air motor 22 to cause saidmotor to rotate capstan 26. Since the particular construction of airmotor 22 is not of the essence of the present invention, no ydetailsthereof are shown. However, for a reason later to be explained, it isnecessary that motor 22 be of the type which will impart a constanttorque to capstan 26 so long as it is supplied with air at a constantpressure. Many such motors are available on the market.

The tool of the present invention is adapted to be used in the samemanner as the tool shown in U.S. Patent No. 2,881,636 to Palmleaf andincludes a strap guiding element 27 carried by casting 10. Guidingelement 27 is provided with a nose `or end 28 adapted to bear against aso-called closed seal to which one end of the strap is connected andthrough which another portion of the strap passes freely. Element 26 isalso provided with a guide slot 29 through which the strap passes beforebeing engaged with one of the slots in windlass 26. Upon rotation of thewindlass -in a counterclockwise direction, as viewed in FIG. 2, thestrap is wound thereabout to tighten it about one or more articlesaround which it has been looped and the seal is then crimped about theoverlapping portions of the strap to secure the same together. This modeof operation is explained in the above-mentioned patent to Palmleaf.

So that the strap may be cut to length after it has been sealed aboutthe article, strap guiding element 27 is provided with a cutter 30.Cutter 30 is in the form of a shaft rotatably mounted in element 27 andhaving a attened surface aligned with slot 29. When the shaft or cutter341 is rotated in a clockwise direction, as viewed in FIG. 2, the edgeof the flattened surface contacts the `strap passing through slot 29 andin cooperation with an edge 31 of said slot is elfective to cut thestrap between capstan 26 and the seal which is butted against the nose28 of guide element 27.

An arm 32 is secured to one end of cutter shaft 30 and said arm carriesa pin 33 engaged with a slot 34 provided in a tab 35 secured to orformed integrally with a leg 36 of a bale 37. Bale 37 constitutes acutter operating handle and has another leg 38 extending parallel to leg36. Legs 36 and 38 are pivotally mounted near their lower ends on pins39 and 40 respectively, secured to and extending outwardly from casting11 of the tool housing. A spring 41 operating between arm 32 and ashoulder 42 of strap guiding element 27 urges cutter shaft 30 to theinactive or non-cutting position shown in FIG. 2 and, through pin 33 andslot 34 of tab 35, urges bale 37 toward the forward position shown infull lines in FIG. l. Movement of the handle 37 to the dotted lineposition shown in FIG. l is effective to operate cutter 30.

Valve 15 comprises a cylindrical member 43 which fits within acylindrical bore 44 extending in from `one side of casting r11, seeparticularly FIG. 6. Member 43 is cutter operating handle 37 to lthedotted line positionprovided with `a groove 45 engaged with which is asetv screw 46 which holds the valve member within bore 44 but permitslimited longitudinal movement thereof. Resilient means in the form of aspring `47 is located between valve member 43 and the inner end of bore44 and` urges member 43 toward the left as viewed in FIGS. 5 and 6, thismovement being limited by the engagement of set screw 46 within `groove45. mentioned conduits 14 and 17 communicate with bore 44 and whenmember 43 is in the position shown in FIG. 5 it `blocks conduits 14 and17 so that compressed air from line 16 cannot reach motor 22. Valvemember 43 is provided with a slot 43 and with a linger piece or manuallyoperable means 49 and when said valve member is pushed inward againstthe laction of spring 47,-

notch 4S becomes aligned with conduits 14 and 17 so that air from line16 may pass through the valve. When Valve 15 is open as shown in FIG. 5leg 38 of bale handle 37 is held against a cylindrical portion of valvemember 43 by the spring 41. When valve member 43 is pushed inward toopen the valve a notch 50 of the valve member becomes aligned with theforward edge `of leg 38 and spring 41 causes leg 38 to move into thenotch to thus hold the valve in open condition. Upon movementof ThehereinbeforeV shown in FIG. 1 to cut the strap as aforesaid, leg 38becomes disengaged from notch 50 and the valve is closed by the spring47.

In use, the tool is engaged with the strap in the manner shown in thePalmleaf patent `and the operator depresses iingerpiece 49 to open Valve15 and thereby cause the strap engaging element or capstan 26 to berotated by motor 22 to tighten the strap labout one or more articlesaround which it lhas been looped. When valve 15 is opened, the notch 50becomes aligned with leg 38 so that spring 41 is able to move said leginto the notch and thereby hold the valve in open condition. Valvemember 43 may be referred to as a motor control member and notch S ofmember `4?; and leg 38 of cutter operating handle 37 constitutecooperating means for holding member 43` in a iirst position, that is,in motor operating position. The air pressure in line 1-6 may beregulated in any suitable manner and the pressure in said linedetermines the rotating force or torque applied by motor 22` to capstan26. When the preselected tension is applied to the strap, as determinedby the pressure in line le, motor 22 will stall and maintain the tensionon the strap while the seal is crimped about the strap. Handle 37 isthen moved rearwardly to the dotted line position shown in iFlG. l tocut the strap to length and this same movement is eiiective to disengageleg 38 from notch 50 .and thereby permit spring `47 to move valve member43 to the position shown in iFIG. 5 to cut oli the supply of air to themotor.

Having thus described a preferred embodiment of the invention, what isclaimed is:

l. Astrapping tool comprising a housing, a strap guiding element on saidhousing, a cutter member associ-ated with said strap guiding element,strap engaging means for pulling la portion of a strap through saidguiding elenient to tighten the same about a package, a motor mounted insaid housing for moving said strap engaging means, a control membermovable to a first position for causing said motor to operate said strapengaging means and to a second position for preventing said motor fromoperating said strap engaging means, resilient means normally holdingsaid control member in its said second position, manually operable meansfor moving said member lto its said first position, a cutter operatinghandle mountedy on said housing, means interconnecting said handle andsaid cutter member whereby movement of said handle to a iirst positionoperates said cutter member, means urging said handle to a secondposition, and cooperating means on said handle and said control memberto hold said control member in its said first position when said handleis in its said second position.

2. A strapping tool comprising 1a housing, a strap guiding element onsaid housing, a slot extending through said strap guiding elementthrough which a portion of a iiexible :strap is adapted to be drawn totighten the same about a package, a cutter member mounted in said strapguiding element for selectively cutting the strap, a windlass fordrawing the strap through said slot, a motor mounted in said housing fordriving said windlass, a control member movable to a rst position forcausing said motor to drive said windlass and to a second position fordiscontinuing the driving of said win-dlass by said motor, resilientmeans normally holding said control member in its said second position,manually operable means for moving said member to its said rst position,a cutter operating handle mounted on said housing, means interconnectingsaid handle and said cutter member where- -by movement of said handle toa first position operates said cutter member, means urging said handleto a second position, and cooperating means on said handle and saidcontrol member to hold said control member in its said rst position whensaid handle is in its said second position.

3. A strapping tool comprising a housing, a strap guiding element onsaid housing, a slot extending through said strap guiding elementthrough which a portion of a exible strap is adapted to be drawn totighten the same about a package, a cutter member for selectivelycutting the stra-p, means for drawing the strap through said slot, saidmeans comprising a uid operated motor mounted in said housing, a-conduit for supplying duid to said motor, a valve in said conduit,resilient means normally positioning said valve so as to prevent thepassage of fluid to said motor, manually `operable means for moving saidvalve to a position to permit the passage of fluid to said motor, acutter operating han-die mounted on said housing, means interconnectingsaid handle and said cutting member' whereby movement of said handle to:a iirst position operates said -cutting member to cut the strap, springmeans urging said handle to a second position, and cooperating means onsaid handle and said valve for holding said valve in position to permitthe passage of fluid to said motor when said operating handle is in itssaid second position.

4. A strapping tool comprising a housing, a seal engaging element onsaid housing, a slot extending through said seal engaging elementthrough which a portion of a flexible strap is adapted to be drawn totighten the same about -a package, a cutter member mounted in said sealengaging element for selectively cutting the strap, strap engaging meansfor drawing the strap through said slot, a motor mounted in said housingfor moving said strap engaging means, a motor control member movable toa first position for activating said motor and to a second position forstopping said motor, resilient means normally holding said motor controlmember in its said second position, manually operable means for movingsaid member to its said iirst position, a cutter operating handlemounted on said housing, means interconnecting said handle and saidcutter member whereby movement of said handle to a first positionoperates said cutter member, means urging said handle to a secondposition, and cooperating means on said handle and said motor controlmember to hold said motor contro-l member in its said first positionwhen said handle is in its said second position.

5. A strapping tool comprising a housing, a seal engaging element onsaid housing adapted to press against a seal with respect to which oneend of a strap is xed and through which another portion of the strap isadapted to be drawn to tighten the strap about `a package, a cuttermember for selectively cutting the strap, strap engaging means fordrawing the strap through the seal, a motor mounted in said housing formoving said strap engaging means, a control member movable to a firstposition for causing said motor to operate said strap engaging means andto a second position for preventing said motor from operating said strapengaging means, resilient means normally holding said control member inits said second position, manually operable means for moving said memberto its said first position, a cutter operating handle mounted on saidhousing, means interconnecting said handle and said cutter memberwhereby movement of said handle to a first position operates said cuttermember, means urging said handle to a second position, and cooperatingmeans on said handle and said control member t'o hold said controlmember in its said first position when said handle is in its said secondposition.

6. A strapping tool comprising a housing, a seal engaging element onsaid housing adapted to press against a seal with respect to which oneend of a strap is fixed and through which another portion of the strapis adapted to be drawn to tighten the strap about a package, a cuttermember mounted in said seal engaging element for selectively cutting thestrap, a windlass for drawing the strap through the seal, a motormounted in said housing for driving said windlass, a motor controlmember movable to a first position for activating said motor and to asecond position for stopping said motor, resilient means normallyholding said motor control member in its said second position, manuallyoper-able means for moving said member to its said rst position, acutter operating handle mounted on said housing, means interconnectingsaid handle and said `cutter member whereby movement of said handle to arst position operates said cutter member, means urging said handle to asecond position, and cooperating means on said handle and said motorcontrol ,member to hold said motor control member in its said irstposition when said handle is in its said second position.

7. A strapping tool comprising a housing, a seal engaging element onsaid housing, a slot extending through said seal engaging elementthrough which a portion of a ilexible strap is adapted to be drawn totighten the same about a package, a cutter member mounted in said sealengaging element for selectively cutting the strap, strap engaging meansfor drawing the strap through said slot, a uid operated motor mounted insaid housing for moving said strap engaging means, a conduit forsupplying ilu-id to said motor, a valve in said conduit, resilient meansnormally positioning said valve so as to prevent the passage of uid tosaid motor, manually operable means for moving said valve to -a positionto permit the passage of fluid to said motor, a cutter operating handlemounted on said housing, means interconnecting said handle and saidcutting member whereby movement of said handle to a rst positionoperates said cutting member to cut the strap, spring means urging saidhandle to a second position, and cooperating means on said handle andsaid valve for holding said valve in position to permit the passage offluid to said motor when said operating handle is in its said secondposition.

8', A strapping tool comprising a housing, a strap guiding element onsaid housing, a slot extending through said strap guiding elementthrough which a port-ion of a flexible strap is adapted to be drawn totighten the same about a package, `a cutter member for selectivelycutting the strap, `a Windlass for drawing the strap through said slot,a fluid operated motor mounted in said housing for driving saidwindlass, -a conduit in said housing for supplying luid to said motor, avalve in said conduit, resilient means normally positioning said valveso as to prevent the passage of uid to said motor, manually operablemeans for moving said valve to a position to permit the passage of fluidto said motor, a cutter operating handle mounted on said housing, meansinterconnecting said handle and said cutting member whereby movement ofsaid handle to a rst position operates said cutting niember to cut thestrap, `spring means urging said handle to a second position, andcooperating means on said handle and said valve for holding said valvein position to permit the passage of iiuid to said m-otor when saidoperating handle is in its said second position.

References Cited in the file of this patent UNITED STATES PATENTS2,036,866 Frost Apr. 7, 1936 2,072,566 Perrelet Mar. 2, 1937 2,929,608Zippel Mar. 22, 1960 2,941,782 Winkler June 2l, 1960

